A ruined medieval chapel found on the largest island, Eilean Fhianain, is dedicated to St. Finan, and may stand on the site of a cell thought to have been built on the island by the saint in the seventh century. The chapel is thought to have been built by Alan MacRuaridh, a chief of Clan Ranald; the clan used the island as a burial place until the end of the sixteenth century. The island continues to be used for burials, and is a Scheduled Ancient Monument.[1]

Acharacle, at the south of the Loch, is the site of the 1140 battle in which Somerled defeated the Norse to found the ruling dynasty of Lord of the Isles.[2] During these times, the loch had strategic importance as a communications route through the mountains, as the short River Shiel was easily navigable in ancient times, however is no longer navigable as the depth drops to less than a foot. In the medieval period the loch formed the boundary between the provinces or lordships of Moidart to the west, Ardgour to the east, and Sunart in the south.

Castle Tioram on the tidal island Eilean Tioram in Loch Moidart, is located so as to control access to Loch Shiel, and thus to Lochaber and the Great Glen, from the sea.[3] The castle appears to have originally been a principal stronghold of Clann Ruaidhrí.[4] According to early modern tradition, preserved by the seventeenth-century Sleat History, the castle was erected by Áine Nic Ruaidhrí (fl. 1318–50), and certainly served as the seat of the latter's Clann Raghnaill descendants for centuries.[5]

Alasdair mac Mhaighstir Alasdair, the poet and Scottish Gaelic tutor of Bonnie Prince Charlie, was born and raised in the area.[6] At the start of the Jacobite rising of 1745, the prince disembarked at Loch nan Uamh and was rowed the length of Loch Shiel in order to raise his standard at Glenfinnan.[7] After the defeat of the rising at Culloden a number of prominent Jacobites, including Cameron of Lochiel, hid on the small island of Eilean Mhic Dhomnuill Dhuibh in Loch Shiel.[8]

In 1842, during the Highland Clearances when tenants were cleared off the land to make way for sheep farming, the women of Loch Shiel apparently drove off the eviction party.[9][10] The women were apparently armed with shearing hooks and aprons filled with stones.[11]